# Test your integration

Simulate card transactions in sandbox environment

Once everything's been set-up, we also provide you with endpoints that allow you to simulate transactions on your card, providing you with data that you can use to better optimize your flows in production.

## Simulate a balance top-up

Fund a balance to use for card spend.

For request/response details, see the [API reference](/api-reference/simulation/simulationbalancetopup).

## Simulate a card transaction authorisation

Simulate POS purchases, e-commerce transactions, ATM withdrawals, and refund authorisations.

For request/response details, see the [API reference](/api-reference/simulation/simulationcardtransactionauthorisation).

## Simulate a card transaction clearing

Clear a previous authorisation. The `ref` field can be copied from the `reference` object in the authorisation response.

For request/response details, see the [API reference](/api-reference/simulation/simulationcardtransactionclearing).

## Simulate a card transaction reversal

Fully or partially reverse an authorisation.

For request/response details, see the [API reference](/api-reference/simulation/simulationcardtransactionreversal).

## Simulate a card transaction refund

A refund is a 2-step process: first authorise with `transactionType` set to `REFUND`, then clear using the clearing endpoint with the same transaction type.

### Step 1: Authorisation

### Step 2: Clearing

For request/response details, see the [authorisation](/api-reference/simulation/simulationcardtransactionauthorisation) and [clearing](/api-reference/simulation/simulationcardtransactionclearing) API references.

## List simulated card transactions

Retrieve recent simulated transactions for a card.

For request/response details, see the [API reference](/api-reference/simulation/simulationcardtransactions).